What is "dreydlekh"

Dreydlekh (plural of "dreidel") or "spins" are musical ornaments of klezmer music, particularly violin, used to produce its characteristic "tear in the voice" sound.

The main dreydlekh are glitshn ( glissandos), krekhtsn ("sobs", "wails"), kneytshn ("wrinkles"), tshoks (a kind of bent notes of cackle-like sound), and flageolets (harmonics).